Gauge block finishing



March 4, 1952 R. GAERLICH 2,588,227

GAUGE BLOCK FINISHING Fil ed Oct. 7, 1949 \z 4 55M/-/-7/v/s//0 505F465 ,i k l jwewr fay/2207a 6452M Patented Mar. 4, 1952 UNITED STATES, PATENT OFFICE GAUGE BLOCK FINISHING Raymond Gaerlich, Jordan, Minn., assignor to Continental, Machines, Incorporated, Savage, Minn., a corporation of Minnesota Application October 7, 1949, Serial No. 120,107

1 Claim.

join the gauging faces with the perpendicular non-gauging faces or marginal. connecting sides by arcuate or bevelled surfaces. This has, to a large extent, eliminated sharp edges and greatly reduced the tendency of the blocks to become burred or nicked. However, even rounding the corners between the gauging faces and the marginal connecting sides has not proved entirely satisfactory for the reason that said rounding must be done prior to final lapping to size and polishing of the gauging faces. Such lapping to size necessarily removes some of theamorphous metal, which necessarily reduces the block some- What in thickness. Therefore, obviously after such lapping, the curved portions connecting the marginal sides with the gauging faces are no longer tangent with said gauging faces-with the result that a small but objectionable edge has been created.

The primary object of my invention is to provide a block wherein the curved surfaces connecting the marginal sides with the gauging faces are such that it is impossible to create any appreciable edge by such lapping and finishing operations.

More specifically, the object of my invention is to provide an arcuate curve extending approximately forty-five degrees from the marginal sides and thereafter connecting said arcuate surfaces with the gauging faces by means of parabolic curves, the portions of said parabolic curves of greatest radii being adjacent the gauging surfaces.

Other objects and advantages of my invention will become apparent from the following detailed specification, appended claim, and attached drawings.

Referring to the drawings:

Fig. 1 is a greatly enlarged fragmentary view in side elevation of a gauge block having the corners between a gauging face and an adjacent marginal face rounded in a conventional manner; and

Fig. 2 is a view corresponding to Fig. 1 but showing a gauge block having said corners formed in accordance with my invention.

It is well known that a selected block of steel must undergo a number of machining and normalizing or seasoning operations in order that a finished gauge block is obtained having a high degree of accuracy and freedom from internal strains which might cause minute but critical.

changes in the dimensions of the finished block. The blocks are machined to a size somewhat greater than the desired finished size, hardened,

so-called finish ground to nearly the required thickness, and seasoned by various heat treatments and aging. The corners between the gauging faces and adjacent marginal connecting sides as well as those between adjacent marginal sides, are rounded to eliminate sharp edges.

This may be done before or after the seasoning operations, as desired. The final mechanical operation in the manufacture of gauging blocks is the lapping of the gauging faces to the exact block thickness required. In Fig. 1, a portion of a conventional gauge block is shown as having a gauging face I and adjacent marginal connecting sides 2 and 3. A semi-finished face 4, shown by dotted lines, is obtained by grinding as above indicated. The corners between the semi-finished gauging faces 4 and adjacent marginal sides are rounded on an arc, said arc being shown between the face 4 and the marginal side 2 and indicated by 5. It will be noted that the are 5 is tangent at one end to the semi-finished gauging face 4 and at its other end to the marginal side 2. When the gauging face is then lapped to final finish, as at I, the tangent therebetween and the are 5 is destroyed and a definite edge or corner 6 is formed. This edge 6, though relatively minute, is objectionable in that it is subject to injury, such as dents, nicks, or burrs, caused by careless handling. Moreover, during the final lapping operation, a certain amount of block material in an amorphous state is pushed out to and beyond the edge 6 where it adheres to the arcuate corner surfaces 5 and forms objectionable burrs. A gauge block produced in accordance with my invention is illustrated in Fig. 2 and comprises a finished gauging face 1, marginal sides 8 and 9, and a cross-sectionally curved corner I0 connecting the gauging face 1 with the marginal side 8. My improved block is built in a manner similar to that described except that the curved corner II] is formed on an are H for approximately forty-five degrees from the plane of the marginal side 8 and on a parabolic curve l2 for the remaining portion thereof. The are H is tangent at one end with the marginal side 8 and at its other end with the end of the parabolic which may have accumulated at the edge portions of the gauging faces and removes the edges formed by the lapping operation. If desired, the parabolic curves may be added to the block before the final finish lapping operation. I have found that this method may be followed with satisfactory results for the reason that any edge formed between the flat gauging face 1 and the adjacent end of the parabolic curve 12 is so minute as to be inconsequential.

I have further found that gauge blocks produced according to my invention have a substantially greater resistance to nicking and burring'at the corners between the gauging faces and connecting marginal sides and a correspondingly longer useful life than conventional gauge blocks.

While I have shown and described a commercial embodiment of my improved gauge block and the method of producing the same, it will be understood that the same are capable of modification without departure from the spirit and scope of the invention as defined in the appended claim.

What I claim is:

A gauge block including a body member having opposed parallel flat gauging faces, side walls intermediate the gauging faces and in normal relation thereto, and curved surfaces between the side walls and the margins of said gauging faces, the curved surfaces as observed in a cross section of the block each including a circular arcuate portion of substantiall extent extending from a side wall in tangent relation thereto and an arcuate portion extending uninterruptedly from the first arcuate portion to the margin of the corresponding gauging face, the second arcuate portion being of substantially greater linear extent than the first arcuate portion and being of increasingly greater radii from the first arcuate portion to the margin of the gauging face, whereby a relatively wide curved surface is provided between the margin of each gauging face and the side walls and the surface defined by said second arcuate portion defines relatively small angles with said gauging face and planes parallel therewith to avoid burr producing impacts with other blocks movable parallel with said gauging face.

RAYMOND GAERLICH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,407,833 Blood Feb. 28, 1922 2,254,894 Johansson Sept. 2, 1941 2,283,289 Roesch et a1 May 19, 1942 OTHER REFERENCES PubL: Do All Burr-Proof Gage Blocks, '7 pages, June 1949, Do All Go, Des Plaines, Ill. 

